Vehicle track assembly

ABSTRACT

A vehicle wheel assembly is provided which includes a vehicle frame having a first axle, a wheel assembly having a housing with an aperture engaging the first axle and enabling the wheel assembly to pivot in a first plane about a first axis formed by the first axle. A cylindrical member is carried by the housing of the wheel assembly, the cylindrical member and housing are arranged perpendicular to the first axle. A first wheel is pivotably connected to a first portion of the cylindrical member and a second wheel is pivotably connected to a second portion of the cylindrical member. The first wheel and second wheel independently pivot in a second plane about a second axis formed by the cylindrical member. The first axis is arranged perpendicular to the second axis and the first plane is arranged perpendicular to the second plane.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/847,264, filed on May 2, 2001, now U.S. Pat. No. 7,740,084 entitledAGRICULTURE IMPLEMENT FRAME, TRACK ASSEMBLY AND CART (as amended), whichclaims priority from U.S. Provisional Patent Application Ser. No.60/201,085, filed May 2, 2000, entitled FRONT FOLDING AND STACKING TOOLBAR, the contents of each are hereby incorporated in their entirety byreference.

BACKGROUND

This disclosure relates to an improved agriculture implement frame andcart. In particular, an improved foldable and stackable frame forsupporting planters, sprayers, or similar devices is disclosed. A noveltrack design that is well-suited for transporting the foldable-stackableframe is also disclosed. A new and improved design for folding wheelsthat are used to support the free ends of the frame is also disclosed.

Foldable frames that are used to support agricultural tools, such asplanters, sprayers, or similar tools are well-known and widely used.Typically, the frames are attached to the rear of a tractor, utilitycart or similar transportation vehicle. The frames have long booms, orwings, that can be adjusted into an extended working position that isgenerally transverse to the direction of travel of the tractor. Theextended wings are too wide to permit convenient transportation whenmoving from field to field, or from storage to the field. Therefore,typically, the wings will adjust into a transport position. In the past,this has generally been accomplished by either folding the wings forwardalong the sides of the transportation vehicle, or by stacking the wingsat the rear of the transportation vehicle. Folding the wings forwardalong the side of the transportation vehicle still leaves the overallwidth wider than the transportation vehicle, because the tools are stilllocated outside the wheelbase of the transportation vehicle. Stackingthe wings may adversely affect the handling characteristics of thetransportation vehicle. The present invention relates to a unique designthat permits the wings to be folded forward, and then stacked, so as tomake the overall width narrower than if the wings were simply foldedforward. Also, the handling characteristics of the transportationvehicle are improved over what they would be if the wings were merelystacked. Furthermore, the arrangement of the wings in the transportposition leaves an unusually large space in the center of thetransportation vehicle for storage of such things as a fertilizer tank,extra seed, or similar items.

The wings may be mounted on a utility cart that can be pulled behind atractor or other pulling device. These utility carts can take manydifferent forms. Most commonly they have a frame on which the wings canbe mounted, and wheels that engage the ground. It is also known tosubstitute tracks or belts for the wheels. One difficulty with thesetracks or belts is that the front and rear of the tracks or belts tendto stay in angular alignment with each other in terms of both pitch androll, which prevents the tracks from closely following the contours ofthe ground. The present invention utilizes idler wheels mounted ontandem arms to support the track. The idler wheels pivot independentlyfrom each other, and allow the track to twist and bend to match thecontours of the ground.

The handling characteristics of the utility cart and tractor combinationcan be improved if the weight distribution between the cart and thetractor is adjustable. The utility cart of the present invention mayinclude adjustable hitch plates that allow the weight distribution to bevaried.

It is common to provide the booms or wings with support wheels near theoutboard end of the wings to provide support for the wings when in use.This disclosure discusses a unique and improved design for folding thesewheels into a transport position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a preferred embodiment of foldable wings mountedon a utility cart according to the present invention showing the rightside wing folded out in working position, and the left side wing isfolded in.

FIG. 1A is a top view of an alternative embodiment of the presentinvention that uses a two-section wing structure and includes foldablewheels on the outboard end of each wing.

FIG. 2 is a partial top view of the rear portion of the embodiment shownin FIG. 1, with the implements removed from the wings.

FIG. 3 is a partial top view close-up of the embodiment shown in FIG. 2.

FIG. 4 is a partial rear view of the embodiment shown in FIG. 2.

FIG. 5 is a rear elevation showing a preferred embodiment of the rearstack assembly in the stacked position.

FIG. 6 is a partial top view close-up of the front portion of theembodiment shown in FIG. 2, with both wings in the folded position.

FIG. 7 is a front elevation of front stacking assembly shown in FIG. 6.

FIG. 8 is a front elevation showing front stack assembly of FIG. 7 inthe stacked position.

FIG. 9 is a top view of the embodiment of FIG. 1A in a transportposition.

FIG. 10 is a side elevation of the frame and cart in the stackedtransport position.

FIG. 11 is a partial cut-away side elevation of the embodiment of FIG.10 adjusted to a lowered position.

FIG. 12 is a front view of the preferred embodiment of FIG. 1 in astacked transport position.

FIG. 13 is a rear view of the preferred embodiment of FIG. 12 in astacked transport position.

FIG. 14 is a partial top view of the right wing pivot and supportassembly of the preferred embodiment of FIG. 1.

FIG. 15 is a partial rear view of the wing pivot and support assembly ofFIG. 14.

FIG. 16 is a partial rear view of the wing pivot and support assembly ofFIG. 14 in a folded position.

FIG. 17A is a side elevation of a preferred embodiment of the wing wheelassembly in lowered position.

FIG. 17B is a side elevation of the wing wheel assembly of FIG. 17A intucked transport position.

FIG. 17C is a top view of the wing wheel assembly of FIG. 17A.

FIG. 17D is a side elevation of a preferred embodiment of a wing wheellift bracket.

FIG. 18 is a partial cut-away top view of preferred embodiment ofutility cart showing left side track assembly.

FIG. 19A is a partial top view showing left front cart and hitch.

FIG. 19B is a partial top view close-up showing details of FIG. 19A.

FIG. 20 is a front elevation of an embodiment of a utility cart.

FIG. 21 is a rear elevation of an embodiment of a utility cart.

FIG. 22 is a side elevation of utility cart.

FIG. 23 is a top close up view of belt tension tube.

FIG. 24 is side view of a preferred embodiment of a lower tandem armthat accommodates both pitch and roll changes.

DETAILED DESCRIPTION

Shown generally in the figures is an improved utility cart 200 for usein association with an improved folding and stacking agriculturalimplement frame 300. The utility cart is suitable for being pulledbehind a tractor or other similar pulling vehicle. With respect to thefigures, right and left designations refer to viewing the cart 200 andimplement frame 300 from the rear looking in the direction of travel.The right and left side of this design are mirrored images of eachother; therefore, the description will concentrate primarily on theright side.

The implement frame 300 is the type that has wings 25, 26 that foldoutward to extend transversely to the direction of travel of the tractorso that several rows of crops can be worked on with a single pass. FIG.1 shows a top view of the cart 200 and implement frame 300 combinationwith a right wing 25 in working position and the left wing 26 still infolded position. Implement frame 300 can have various implementsattached for numerous uses such as fertilizer spraying, pesticidespraying, planting, and other uses. For these illustrations, planterunits 202 are shown. The wings 25, 26 can be varied in length toaccommodate different row spacings and number of rows.

As best seen in FIG. 2, the wings 25, 26 comprise a wing tool bar 204and a wing support bar 206. The planter units 202, or other implements,attach to the wing tool bar 204. According the embodiment shown in FIG.2, a rear tool bar 78 is attached to the rear of the cart 200 to permitattachment of implements. When in full working position, both wings 25,26 are folded out or back perpendicular to the main lift arms 56, 57 andin line or parallel to plane of the rear tool bar 78. Alternatively, therear tool bar 78 may be eliminated, and the left and right wings 25, 26can be extended inboard. (FIG. 1A). In planting position, wing lock arms29, 30 are unfolded and held in a straight or slightly overcenteredposition by the wing lock arm hydraulic cylinder 28. Front wing lock arm30 is attached to a ball swivel in a plate 33 extending from front winghold assembly 51. Ball swivel and plate 33 are almost directly in adirect line with the pin 19 in the wing pivot assembly 90. This allowsthe entire wing 25 to go up and down following the terrain withoutbinding.

The raised/lowered position is controlled by two hydraulic cylinders 67,68 which extend and raise main lift arms 56, 57. (FIG. 13). The right 67and left 68 main lift cylinders are attached to main frame rails 60, 61by plates of steel 69, 70 on each side of the cylinder with pin 71placed in holes in plates 69, 70 and through round sleeve on butt ofcylinder forming a pivot. Ram of cylinders 67, 68 attach to a pivotplate 81, FIGS. 10 & 11, which is optional and could be attacheddirectly to main lift arms 56, 57. But pivot plate 81 acts as a manualextra flex in uneven terrain. Raising and lowering can be accomplishedby placing a lift wheel behind rear main support frame 1 and/or reartool bar 78 in many different configurations.

Wheel lift assemblies 400 (shown in FIG. 1A and further detailed in FIG.17) are placed on the outboard end of wings 25, 26. Placing of assemblyor type of assembly can vary. The wheel assembly (FIG. 17) preferablyraises and lowers simultaneously with main frame. These wheel liftassemblies are described in greater detail below.

To get to transport position, wings 25, 26 are folded in. The left sideis shown in folded position in FIG. 2. Hydraulic wing fold cylinder 23(FIG. 14), is retracted, wing 25 is pivoted on pin 17 of wing pivotassembly 90. Pin 17 also extends through wing pivot support assembly 22to form a pivot. Part of wing pivot assembly 90 is wing flex sleeve 21(FIGS. 14 and 16). Pin 19 extends through sleeve 20 and through wingflex sleeve 21 and through round sleeve 39 in wing 25 (FIG. 15). Thisallows wing to pivot up and down to follow contours of land or whateverapplication requires. Before hydraulic wing fold cylinder 23 canretract, the wing lock arm hydraulic cylinder 28 has to retract andbegin folding the lock arms 29, 30 inboard. A hinge allows lock arm 29,30 to pivot in a horizontal plane with wing 25 (FIG. 2).

The wing fold cylinder 23 attaches to a plate extending out from wingpivot assembly 90 (FIG. 14). The cleaves end of the butt of the cylinderattaches to a welded ball swivel 82 in the plate. This allows for thewing to flex up and down. The ram end of the cylinder attaches to a ballswivel in flex arm 24 which pivots on a pin 84 which is between twoplates of steel with holes forming hinge. This also allows for wing flexwithout the cylinder extending or retracting during field operations,which is optional in the design.

When cylinder 23 is fully retracted, the wing frame 25 is over and up tonotch in front wing hold assembly 51. This can have many differentdesigns to hold wings to the assembly 51 but had to be able to lift thewing 25 in an arcing vertical movement. (FIGS. 6, 7 and 12).

When wing 25 is on the front wing hold assembly 51 the wing lock arms29, 30 are fully inverted by the wing lock hydraulic cylinder 28 so theyare parallel or close to parallel to the wing 25. Then the stackinghydraulic cylinders 15, 50 can be extended simultaneously usingrephasing cylinders or master slave cylinder. The butt end of cylinderhas a sleeve or cleaves so it may pivot as cylinder is actuated. It isheld by a pin 9, 53 which passes through a sleeve or holes in theinboard ends of the rear and front bottom stacking arm 4, 75 and alsothrough holes or bushings in the steel plates that form rear and frontmain support frames 1, 2. The cylinder ram pivot 87, 88 is at the end ofthe ram of the stacking cylinders 15, 50. It can be a sleeve or cleaveswhich is held by a pin 38, 54 which passes through welded sleeves 36, 37and 44, 45 which are attached by metal plates welded to the top of thestacking arm 3, 74 shown best in FIGS. 3, 4, 6 and 7.

The top stack arms 3, 74 are attached by pin 10, 52 which extendsthrough sleeve or holes in the stack arms 3, 74 and through a hole orbushing in the upright plates of steel that form the main support frame1, 2.

The outboard ends of both the top and bottom stack arms, front 74, 75and rear 3, 4 have round sleeves and 11, 13 and 12, 14 or holes whichpins 34, 35, 55, and 89 extend through. In the front, stack arms 74, 75pin 55, 89 also extend through holes or bushings in the front wing holdassembly 51 FIGS. 6 & 7. The rear stack arms 3, 4 are similar to thefront. Pin 34, 35 extends through hole or bushings in the wing supportpivot assembly 22.

Both front and rear, top and bottom stack arms 3, 4 and 74, 75 aresimilar in length and hole or bushings in main support frames 1, 2 andfront wing hold assembly 51 and wing pivot support assembly 22 arematched in these illustrations which keep the wing frame 25perpendicular to the main frame through the entire vertical arc of thestacking movement. By varying the length between the pivot points,frame, top stack and bottom stacking arms, the angle of the wing framecould be pitched up or down through the vertical arc of the stacking armand would accomplish the same basic principle.

When the stack cylinders 15, 50 are extending close to the top of thearc, they continue to pass top of center and over center (FIGS. 5, 8 and9). Gravity helps to keep the wings 25, 26 in the transport positioneven though there is still pressure via trapped oil within the stackcylinder which will also hold wings 25, 26 in transport position (FIG.10).

Going over center is not totally necessary and in some uses other framesmay not be designed this way, which would increase the distance betweenthe wings 25, 26 in transport position or to narrow main support frameso that total transport width may be narrower.

Unstacking the wings 25, 26 is performed by applying pressure to thehydraulic oil on the ram side of the stack cylinder 15, 50 so that theyretract simultaneously until they are totally retracted and the stackarms 74, 75 and 3, 4 are horizontal (FIGS. 4 & 7). The bottom stack arms75, 4 rest on the retracted stack cylinder 15, 51 and also steel plate72, 73 that extend out from the bottom of the main support frame 1, 2(FIGS. 12, 13). Also, the tube that connects both sides of stack armsmay be welded in a manner that they rest on the vertical plates thatform main support frame 1, 2, but in an area where they do not conflictwith the stack cylinders 15, 51 in any of their range of arc.

The front wing hold assembly 51 must be slightly lower than the heightof the wing frame 25 at the point where they connect (FIG. 7). Nowpressure can be applied to the hydraulic oil on the ram side of the wingfold cylinder 23 which extends it out and pushes the flex arm 24 againstthe unfolding stop 27 which is made by welding steel plates to the wingframe 25. As the wing fold cylinder 23 continues to extend, the wing 25pivots on pin 17 in the welded sleeves 18 of the wing pivot assembly 90(FIG. 15). The wing pivot assembly 90 is also connected by pin 17 to thewing pivot support assembly 22. The wing lock cylinder 28 is alsoextending at the same time as wing fold cylinder 23. When the wing 25 isin the working position (FIG. 2) shown perpendicular to main lift arm 56the wing lock cylinder 28 is fully extended and front lock arm 30 andrear lock arm 29 at center lock arm hinge 32 are straight or slightlypast center. The unfolding of the wings 25, 26 should be performed withthe planting units off the ground so not to create more resistance.

The main frame has many parts. The base frame 60, 61 rest on the framerails 65, 66 of the utility cart. As an alternative, these frame rails65, 66 may be mounted so that their tops are angled slightly inwardly.The base frame members 60, 61 must be correspondingly angled in thisinstance, as shown in FIGS. 20 and 21. Angling the frame rails inwardfacilitates mounting the base frame 60, 61 because it will help alignthe frame rails with the base frame 60, 61 if they are slightly offalignment. The leading edges of the frame rails 65, 66 may be similarangled in order to help base frame 60, 61 align both side-to-side andfront-to-rear. When using a removable cart assembly (these drawings usea tracked cart for the carriage) the base frame 60, 61 and frame rails65, 66 could be combined for the purpose of a permanent carriage.

The base frame 60, 61 is attached to the front main support frame 2 bypins 79, 92 which extend through plates of steel welded to the bottom ofthe main support frame. Pins 79, 92 extend through holes in plates ofsteel and then through a hole or sleeve in the base frame 60, 61. Thisforms a pivot or hinge. (FIGS. 11, 12).

The front main support frame 2 is attached to the main lift arms 56, 57near the front of frame. These positions can be varied to meet differentlengths of wings or different carriage lengths or many other needs.

The rear main support frame 1 is mounted at the rear main lift arms 56,57 (FIGS. 10, 11). The main support frames 1, 2 must be parallel.Further, their vertical planes must be parallel [though not necessarilyperpendicular to main lift arms 56, 57 or base frame 60, 61] so thatfront 74, 75 and rear 3, 4 stacking arms in their arcing movement remainparallel.

The main lift arms 56, 57 and base frame 60, 61 can be designed in manydifferent ways and the design shown in FIG. 11 is not the only pertinentdesign. The main lift arm 56, 57 must be strong enough to carry all theweight of the wing frames 25, 26 and attachments to the wings.

Behind the rear main support frame, this design uses an implement tube78 for mounting units.

The base frame 60 rests on the cart frame 65 and is attached aspreviously described. Extending down parallel from base frame rail 60 isa plate of steel which extends down to the sleeve 91 (FIG. 13) on thebutt end of the main lift cylinder 67. Welded to this plate is anotherplate which is perpendicular to the first. Welded to this plate isanother plate perpendicular to the last that forms a “U” shape. Thisassembly forms a support for the main lift cylinder 67. Pin 71 extendsthrough holes or bushings 69, 70 in the steel plates and through thesleeve 91 on the butt end of the main lift cylinder 67. Pin 71 is at a90 degree angle to the base frame allowing the main lift cylinder topivot parallel to the base frame 60. On the extended plate that is 90degrees from the base frame rail, a horizontal plate should be welded ina manner that it rest and gain support from the rear main carriage axle58. Also sleeve 91 should be slightly oversized to allow for some sideto side sway. The above described supporting of the main lift armcylinders 67, 68 can be accomplished by other methods.

The wing wheel lift assembly illustrated in FIGS. 17A-D is unique and iswell suited for this tool bar design but is not the only acceptablemethod of raising and lowering the wing frame 25, 26.

The wing wheel lift assemblies for wings 25, 26 are identical, so onlyone will be described here. The leading wheel 141 and the trailing wheel142 both caster or swivel 360 degrees in either direction. The leadingand trailing wheels 141, 142 are illustrated using a standard fork typemounting 143, 144. A single offset arm and spindle caster could be used.The leading wheel 141 and fork 143 swivels on a vertical shaft 145 thatextends through a round sleeve 147 which is attached to an outboardbracket 151. The outboard and inboard brackets 151, 152 are mirrorimages and both are somewhat “U” shaped. This allows the leading wheelhydraulic cylinder 154 space for its movement. These brackets 151, 152are connected to upper and lower parallel link arms 149, 150 by pins153A-D which extend through holes or round sleeves in the ends of theparallel link arms 149, 150 and through holes in the outboard andinboard brackets 151, 152. In these illustrations, the butt end of theleading wheel hydraulic cylinder 154 pivots on pin 153D and the ram endpivots on pin 153B. The end of the cylinder could be attached and pivoton separate pins and still conform to this design. This type design usesparallel link arms to keep the caster wheel at a constant vertical anglewhich is not unique. What is unique is that the inboard bracket 152 alsopivots or swings in and out perpendicular to the frame on pin 153D.(This pivot could be placed in a different pin or sleeve but stillconform to this design.) (FIGS. 17A & B).

Pin 153D extends through holes in plates of steel which are vertical andare outside of upper and lower parallel link arms 149, 150 and arespaced far enough apart and in front of wing frame 25, 26 that it canpivot or swing inward in an arcing movement perpendicular to the wingframe 25, 26. These plates of steel are part of the wing wheel liftbracket 163 (FIG. 17D).

The bottom of the inboard bracket 152 is attached by pin 162 to bracket167 which is attached to the back or inboard side of inboard bracket 152by pin 162 which extends through a hole in wheel tucking link arm 165forming a pivot. The other end of the wheel tucking link arm 165 isattached to the wheel tucking lever 164 by pin 160 which extends throughholes in both 164, 165 which also forms a pivot. (FIG. 17C).

The wheel tucking lever 164 is attached to the wing wheel lift bracket163 by pin 161 which extends through brackets 168A&B that are attachedto wing wheel lift bracket 163 and through a hole at the bottom of thewheel tucking lever 164 forming a pivot. At the top of the wheel tuckinglever 164 is another hole where the butt end of the trailing wheelhydraulic cylinder 156 is attached by pin 159. The ram end of thetrailing wheel hydraulic cylinder 156 is attached to a plate or platesof steel extending vertically from the trailing wheel arm 155 by pin 158which extends through holes in the plates of steel and through the yokeor sleeve 170 at the end of the ram. (FIGS. 17A-C)

The inboard bottom end of the trailing wheel arm 155 is attached by andpivots on pin 157 which extends through holes in the outboard ends ofthe wing wheel lift bracket 163 and in a round sleeve 169 attached totrailing wheel arm 155. This allows the trailing wheel arm 155 avertical arc perpendicular to the wing frame 25, 26.

At the outboard end of the trailing wheel arm 155 is a round sleeve 148which is attached in a way that the vertical caster shaft 146 extendsthrough the round sleeve 148 and is for the most part straight up anddown when the wing 25, 26 is in the up working position. Like theleading caster wheel 141 the trailing wheel 142 can swivel 360 degreesin either direction.

The leading and trailing wheel 141, 142 run in the same path in astraight route of travel reducing the total width of wheel tracks andalso reduces the amount of drag caused by wheels running in loose soil.

The hydraulic cylinders leading 154 and trailing 156 receive hydraulicoil from the ram side of the right or left main lift cylinder 67, 68.This hydraulic oil is trapped and flows in and out of the butt ends ofthe leading 154 and trailing 156 hydraulic cylinders. In theseillustrations, the bore and stroke of the hydraulic cylinder 154, 156are different sizes, but the volume of hydraulic oil it takes to movethe leading and trailing wheels 141, 142 is the same. In the workingpositions up or down on level ground the rams of neither the leading ortrailing hydraulic cylinders 154, 156 are fully retracted or extended.This allows for movement of the wheels up and down so to traverse unevenground keeping the wing frame 25, 26 from being jarred or bounced overbumps. When the leading wheel 141 rolls over a rock or bump, hydraulicoil is displaced from the leading hydraulic cylinder 154 to the butt endof the trailing hydraulic cylinder 156 and it moves down the same amountthat the leading wheel 141 moves up. It works a similar way when thelead wheel 141 passes through a hole or dip because this puts morepressure on the trailing wheel, it pushes the ram in and displaces oilfrom the butt of the trailing hydraulic cylinder 156 to the leadingwheel hydraulic cylinder 154 because of the reduced pressure in thehydraulic cylinder 154. All this creates a hydraulic walking tandem typesituation.

The unique operation of this wing wheel lift assembly is the wheeltucking for transportation in the stacked position (FIGS. 9 & 17D). Inthe working position (FIGS. 17A & B) the wheel tucking lever 164 is heldagainst the stop adjustment bolt 166 by the pressure of the trailingwheel arm 155. This pressure, caused by leverage, holds the inboardbracket 152 of the leading wheel assembly in a vertical position bypressure transfer from the wheel tucking lever 164 to the wheel tuckinglink arm 165.

When the wing frames 25, 26 are being stacked, the pressure is taken offthe wheels as the wing frame rises. The trailing wheel arm swings downand in pulling the wheel tucking arm 164 back. At the same time thispulls the inboard bracket 152 back and up. This causes the lead casterwheel 141 to be tucked under the wing frame 25, 26 (FIG. 17D). This mayalso create a suction effect by further pulling the leading wheelhydraulic cylinder 154 in because the weight of the trailing wheel willpull the ram of the trailing wheel hydraulic cylinder 156 out, creatinga need for additional hydraulic oil in the butt side of the hydrauliccylinder which should suck the oil out of the butt end of the leadingwheel hydraulic cylinder 154.

In unstacking, the trailing wheel 142 makes contact with the groundfirst. As the wing frame 25, 26 gets closer to the ground the trailingwheel arm 155 pushes the ram of the trailing wheel hydraulic cylinder156 in, displacing oil to the leading wheel hydraulic cylinder (154 alsopushing the wheel tucking lever 164 inward towards the stop bolt 166.This through the wheel tucking link arm 165 pushes the inboard bracket152 of the leading wheel assembly down and forward back to the verticalposition.

This frame design is not limited to a utility cart, more so a tracked orbelted cart, though due to the ability of the tracked vehicle to carrylarge loads, a tracked utility cart was used in all of the drawings. InFIG. 18 a plain top view of the cart shows the left side (as determinedby viewing from the rear looking in the direction of travel) with thebelts cut out so that the front 122A&B, rear 123A& B and idler 124A-Hwheels can be shown. The right side is a minor image of the left. Alsoshown are the front hubs 101A&B, rear hubs 103A&B and idler hubs 102A-H. The hubs run on shafts that have spindles machined on both ends toform a short axle. FIG. 19A shows a close up view of the front axlespindle 112, which extends through holes or round sleeve 116A in the topleft tandem arm 120. This top tandem arm 120 is parallel with the cartframe 66 and pivots on pin 111, which extends through a round sleeve 110or holes. The rear of the front top tandem arm 120 extends down toanother pivot formed by pin 129 and round sleeve 115. (FIG. 19A). Pin129, 129A extends through holes in steel plates that extend up from theleft front lower tandem arm 118 and then through round sleeve 115 in thebottom of the front top tandem arm.

A preferred design for the lower tandem arms 118, 119 is shown in FIG.24. Each tandem arm includes an upper portion 208 that pivotally mountsto the top tandem arms 120, 121. Attached below the upper portion 208 isan outer roll tube 210. An inner roll tube 212 slides into the outerroll tube 210, and is free to rotate within the outer tube 210. A firstaxle attachment member 214 is fixedly attached to one end of the innerroll tube 212, as by welding. A second axle attachment member 216 ispivotally attached to the opposite end of the inner roll tube 212, andheld in place by end cap 218, so that the first and second axleattachment members 214, 216 can pivot with respect to each other aboutthe axis of the inner roll tube 212. Idler hub spindle axles 113A&B areattached to the first and second axle attachment members 214, 216.

An alternative design for the tandem arms 118, 119, which does not allowfor roll along a longitudinal axis is also possible. According to thissimpler design, at each end of the front lower tandem arm 118 are holesor round sleeves (117A&B which the idler hub spindle axles 113A&B extendthrough. The rear lower tandem arm 119 is identical to the front lowertandem arm 118 using round sleeves 117C&D and idler hub spindle axles113C&D.

The left rear top tandem arm 121 and rear lower tandem arm 119 areconnected at pivot formed by pin 129B and round sleeve 115B. The leftrear top tandem arm 121 also like the front top tandem arm 120 pivots onpin 111 which extends through round sleeve 137. At the opposite end fromround sleeve 115B in the left rear top tandem arm is round sleeve 116Bwhich the left rear hub spindle axle 138 extends through. All of thebefore mentioned pivots follow the arms to move in the same verticalplane (FIGS. 20 & 21) which runs parallel to cart frame 66. This allowsfor the inner sides of the pairs of wheels front 122A & B, rear 123A &B, idlers 124A & B, 124C & D, 124E & F, 124G & H to form guides for theguide blocks 139A-D (FIGS. 20 & 21) which are aligned down the centerand all the way around the inside of the belts which is somewhatstandard on belts.

Because of the multiple pivot in the vertical plane the pairs of wheelscan move up and down traversing the ground with more equal weightdistribution and still guide the belts.

The top tandem arms 120, 121 are connected to the main cart pivot axles,front 59 and rear 58 by pins 111 and 132. Both pins are held in roundsleeves, front 109 and rear 131. A bolt or pin may be placed in a holedrilled through the pin and sleeve or pin 111 and pin 132 may bedirectly fastened to the main cart pivot axles 58, 59. FIG. 23 shows topview, FIGS. 20 and 21 show front and back elevation.

The cart frame rails 65, 66 can be attached in many different ways suchas bolt or welded to main cart pivot axles 58, 59 or bolted indirectlyso to use load cells for a weigh scale. The method that will bedescribed and illustrated uses additional pivots to allow for smootherload transporting in uneven terrain. Also this design allows the sameweight to be transferred to or from the draw bar of the vehicle pullingit by moving the front frame pivot assemblies 127, 128 forward orbackward on the adjustable hitch load plates 125, 126.

The adjustable hitch load plates 125, 126 have holes drilled in them soto allow the front frame pivot assembly 127, 128 to be bolted inincremental positions but staying perpendicular to main cart frame rail65, 66. (FIGS. 19 & 20). The front frame pivot assemblies 127, 128 areconnected to the front load pivot assembly 96 by pin 106, 107 forming apivot in round sleeve in the front frame pivot assemblies 127, 128.These round sleeves are perpendicular to the main cart frame rails 65,66. The pins 106, 107 also extend through round sleeves 104, 105 whichmay be drilled and bolted securing the pins 106, 107. It would possibleto substitute a single long rod for pins 106 and 107. The pins 106, 107may be fastened directly to the front load pivot assembly 96 (FIGS. 19 &20). The side elevation in FIG. 22 also shows all of this in a cut awayview.

The front load pivot assembly 96 can slide forward and backward on thefront slide pivot axle 95. In this design the pull is transferred fromthe hitch 62 to the front main pivot axle 59 to the front top tandem arm120 to the front wheels 122A, B which pull the belts 63, 64 and the restof the cart rides on the belts 63, 64. This helps the belts to track orguide easier. This is not totally necessary and may be designeddifferently.

The front slide pivot axle 95 extends through a hole or round sleeve 94in the hitch cross member 100 and round sleeve 108 in the front loadpivot assembly 96 and into a hole or round sleeve 93 attached to frontmain cart pivot axle 59. The front slide pivot axle 95 is centeredbetween and parallel to the main cart frame rails 65, 66 (FIG. 19). Thisdesign permits the weight distribution to be adjusted between the cartand the pulling vehicle. By adjusting the location of the front framepivot assemblies 127, 128 forward or rearward on the adjustable hitchload plates 125, 126, the distribution of the weight can be shiftedforward or rearward. As an alternative, it would be possible to add anadditional cross member (not shown) to the hitch 62, similar to crossmember 100, and mount the front slide pivot axle 95 between the twocross members instead of between cross member 100 and the front maincart pivot axle 59.

The hitch 62 (which can be varied in length) is attached to the frontmain cart pivot axle 59 and extends forward. Illustrated in FIGS. 18 &19 is the adjustable length hitch, where an outside hitch tube 97 isincorporated in the design of the hitch 62 and internal hitch tube 98can be extended or retracted to different lengths.

The rear main cart pivot axle 58 can be attached in many ways to themain cart frame rails 65, 66. If using a design similar to this andusing a front pivot, the main frame rails 65, 66 should be mounted in aridged way. Shown in FIG. 21 a frame cross member 133 helps support themain cart frame rails 65, 66.

FIG. 23 illustrates a necessity of design which is a belt tensionassembly. This may be designed in a different way and placed in adifferent position. It serves to keep tension on the belts and to keepthem guided between the wheels of the carriage. It should extend betweenthe front and rear main cart pivot axles 58, 59. This illustration anddesign shows arms (plates of steel) extending from a round tube, and pin132 extending through holes in the plate or round sleeve 140A & B. Thisassembly is the external belt tension tube 134. In the same manner, theinternal belt tension tube 135 is built and pivots in hole or roundsleeves on pin 111 which is attached to the front main cart pivot axle59. The arms of both the internal and external belt tension tubes 135,134 straddle the front and rear top tandem arms 120, 121. These tensiontubes 134, 135 do not have to straddle the top tandem arms 120, 121 andmay be placed on either side and may be pinned directly to the front andrear main cart pivot axles 58, 59.

When the belts are tensioned, a clamp 136 or some type of stop must beplaced on the section of internal tension tube 135 sticking out of orpast the end of the external tension tube 134. These tubes must be ableto rotate inside each other to allow for the uneven movement up and downof the main cart pivot axles 58, 59.

This cart design could be built using only one top and bottom tandem armor two top and one bottom tandem arms with a single axle attached at thebottom of the top tandem arm. This would allow for a shorter cart base.When using only one top and bottom tandem arm, one main cart pivot axlewould extend out and attach to a hub and spindle which would attach toboth the inboard and outboard (front or back) wheels.

1. A track assembly for a vehicle, the track assembly having alongitudinal axis and comprising: a. a single piece endless trackdefining a ground engaging run, the ground engaging run having: i. firstand second lateral edges and an outer ground engaging face extendingbetween the first and second lateral edges, the outer ground engagingface defining a surface that is continuous and uninterrupted over itsextent; ii. an inner face including: a. a track guide projectinginwardly from the inner face, the track guide being located between thefirst and second lateral edges; b. a first generally flat and horizontalsupport wheel engaging surface extending between the first lateral edgeand the track guide, the first support wheel engaging surface beingcontinuous and uninterrupted over its extent; c. a second generally flatand horizontal support wheel engaging surface extending between thesecond lateral edge and the track guide, the second support wheelengaging surface being continuous and uninterrupted over its extent; d.the first support wheel engaging surface and the second support wheelengaging surface being generally co-planar and being generally parallelto the outer ground engaging face, the track guide having a tip portionvertically inwardly spaced apart from the first support wheel engagingsurface and from the second support wheel engaging surface; b. a supportwheel arrangement engaging the ground engaging run, the support wheelarrangement including: i. a first support wheel mounted for rotationabout a first axis that is generally transverse to the longitudinal axisof the track assembly, the first support wheel having a generallycylindrical peripheral surface that is in rolling contact with the firstsupport wheel engaging surface, the first support wheel engaging surfacebeing characterized by a width, the generally cylindrical peripheralsurface of the first support wheel extending over a major portion of thewidth of the first support wheel engaging surface; ii. a second supportwheel mounted for rotation about a second axis which is parallel to thefirst axis, the second support wheel having a generally cylindricalperipheral surface that is in rolling contact with the second supportwheel engaging surface, the second support wheel engaging surface beingcharacterized by a width, the generally cylindrical peripheral surfaceof the second support wheel extending over a major portion of the widthof the second support wheel engaging surface; iii. the first and secondsupport wheels being spaced apart to define therebetween a void area forreceiving the track guide; c. the first support wheel and the secondsupport wheel being mounted for pivotal movement via a pivot structureabout a third axis which is generally perpendicular to the first axisand to the second axis, the third axis being vertically spaced apart inan inward direction from the tip portion of the track guide.
 2. A trackassembly as defined in claim 1, wherein the third axis is spaced apartvertically inwardly from the first axis.
 3. A track assembly as definedin claim 2, wherein the first support wheel and the second support wheelpivot in unison about the third axis.
 4. A track assembly as defined inclaim 3, wherein the first support wheel and the second support wheeldefine a first wheel set, the track assembly further comprising a secondwheel set, the first wheel set and the second wheel set being mounted toa tandem arm capable of pivotal motion about a fourth axis which isgenerally parallel to the first axis.
 5. A track assembly as defined inclaim 4, wherein the first wheel set and the second wheel set pivotindependently about the third axis.
 6. A track assembly as defined inclaim 1, wherein the second axis is co-linear with the first axis.